The short answer is: to prevent Austria from passing a law that would prevent it from unifying with Germany.
The longer answer with the background info:
In the late 1920s and early 1930s, as Nazism grew in popularity in Germany, it likewise grew in neighboring Austria. Just after Adolf Hitler and the Nazis took control of Germany in early 1933, an Austrian leader named Engelbert Dollfuss became the chancellor of Austria. He was worried that Austrian Nazis would push for Austria to join Germany (even though the treaties ending World War I had forbidden it), so he formed a new political party called the "Fatherland Front" and made himself into a dictator in a manner very similar to Benito Mussolini's Fascist Italy. This was nicknamed "Austrofascism".
Due to the similarity between Austrofascism and Fascism, the two dictators (Dollfuss and Mussolini) became friends, and Mussolini sought to prevent Germany from trying to annex Austria. In July 1934, Nazis murdered Dollfuss, and Italy nearly went to war with Germany over it. Austrian Nazis attempted to take over Austria in the aftermath of the assassination, but were defeated when the military said they would simply blow up the building they were in. The new chancellor, Kurt Schuschnigg, continued Dollfuss's Austrofascist Dictatorship.
The Austrian Nazis did not quit however. They continued trying to take control of Austria so that it could be merged with Germany. In March 1938, Schuschnigg had had enough of their trouble-making, and decided to let the Austrian people vote to decide to permanently forbid Austria from joining Germany. However, he included rules that made it difficult for Austrian Nazis to vote, and these Nazis basically went to Hitler to complain.
In the years between 1935 and 1938, Mussolini had become friends with Hitler, so Italy was no longer strongly backing Austria's independence. Freed from outside interference, Hitler issued an ultimatum to Schuschnigg: cancel the vote, or Germany will invade. Schuschnigg refused to cancel the vote, and the day before the election, Germany's military invaded. Schuschnigg ordered his military not to resist, because it would've led to a bloody war that Austria couldn't win. Austrian Nazis enthusiastically greeted the invading German troops, which caused the invasion to be nicknamed the "Blumenkrieg" ("Flower War").
On April 10, 1938 (just a few weeks after the invasion), Hitler held his own election in Austria, in which the Austrians would instead vote on whether or not to join Germany. The election was not really a fair election- ballots were not done in secret, and government officials stood watch to make sure that everyone voted "correctly". The vote wound up passing in favor of unification by 99.7%- a sure sign of a fraudulent election. But the vote counted, and Austria was officially annexed by Germany.
Well, two main reasons.
There was a time in the the 1940's when Hitler was in power. He decided to do this on March 19th, 1944.
Because Hitler was born in Braunau, Austria.
That was his homeland.
No, it was in 1939.
They invaded Hungray
he really invaded Poland Hungary and other neighboring places but he did not invade the USA
Paratroopers (fallschirmjäger)
The Germans did not invade North America during WWII.
2001
400 a.D.
No, it was in 1939.
They invaded Hungray
yes
Never.
September 1st 1939.
1941
Through the Belgian Ardennes.
New Zealand invade Samoa to defeat the Germans and rule them.
The Channel Islands, Jersey and Guernsey. In the Mediterranean the Germans also pounded Malta from the air, but did not invade. The British and Germans had a vicious battle on the Greek island of Crete, which the Germans won, ejecting the British.
he really invaded Poland Hungary and other neighboring places but he did not invade the USA